This invention relates to a solar cell for use in converting optical energy into electrical energy.
A conventional solar cell comprises first and second members opposite each other and an amorphous silicon lamina between the first and the second members. The first and second members serve as electrodes. In such a solar cell, a predetermined one of the first and the second members should be transparent in order to expose the amorphous silicon lamina to light and to generate electromotive force across the first and the second members.
It is preferable that the solar cell have a high conversion efficiency of optical energy to electrical energy. Various attempts have been directed to improvement of characteristics of the amorphous silicon lamina so as to increase the conversion efficiency. In other words, such attempts have practically left the first and the second members out of consideration. The conversion efficiency increases to some extent by improving the characteristics of the amorphous silicon lamina. However, an increase of the conversion efficiency as a result of such efforts, reaches a limit. In addition, the conversion efficiency of each solar cell is extremely variable even when the amorphous silicon lamina is deposited under the same conditions.